5.7 v8 mercruiser

[Johnson110]

Question, I was ruunning my engine on the muffs, temp ruuns a high of 160 then drops to 150, the pump is two years old, just about ready to launch the boat. Is it time to do pump again or can I get a season out of it. Thanks

 

[cooter2506]

Re: 5.7 v8 mercruiser

I would change the pump and see where it goes from there. Pump should be changed yearly or at the least every two. Also what tstat is in it 160 or 140. If in salt water you should have the 140.

 

[Johnson110]

Re: 5.7 v8 mercruiser

Thanks, I think it is a 160 thermostat, The boat was serviced buy a marina, I brought it last year, but I did the maintance on it my self. The pumpp was changed in 07, I used the boat not a whole lot last year, it is docked in salt water, In 06 the previous owner had the heads redone the manifolds had 3k worth of work done to it, it is saltwater cooled, had no problems with it last year!

 

[Don S]

Re: 5.7 v8 mercruiser

What year and drive????

If it's an engine mounted pump, everyother year would be max recommended use. 90 and older Alpha type, same thing.
91 and newer Alpha I Gen II drives, the impeller is not the problem

Could also be the thermostat sticking open. Better than closed, but could still be a problem.

 

[Johnson110]

Re: 5.7 v8 mercruiser

The engine is a alpha 1, the year is 1995, the water pump in the lower unit was done in year 07, so this would be its third year in use!

 

[Johnson110]

Re: 5.7 v8 mercruiser

What should the temp read while running on muffs.

 

[Don S]

Re: 5.7 v8 mercruiser

What should the temp read while running on muffs.

Hard to say, depends on the water pressure and volume you have. Put it in the water and see what it does.